Cellulosic paper sized with an alkyl acrylate or propiolate and a polyalkyleneimine



3,461,029 CELLULOSIC PAPER SIZED WITH AN ALKYL ACRYLATE R PROPIOLATE ANDA POLY- ALKYLENEIMINE William Robert Hine, Jr., Kirkwood, and Myron J.Holm, St. Louis, Mo., assignors to Monsanto Company, St. Louis, Mo., acorporation of Delaware No Drawing. Filed Oct. 21, 1965, Ser. No.500,209 Int. Cl. D2111 3/46, 3/40; D21d 3/00 U.S. Cl. 162168 11 ClaimsABSTRACT OF THE DISCLOSURE A composition comprising an alkyl acrylate oran alkyl propiolate and a polyalkyleneimine which is useful in thepreparation of sized cellulosic paper substrates.

This invention relates to the sizing of cellulose paper substrates. Moreparticularly this invention provides new combinations of materials whichare very effective as sizing agents, especally under neutral andalkaline conditions of papermaking.

Much of the cellulosic paper produced at the present time is preparedunder acid conditions, that is, with pulp slurries having pHs in therange of from about 4.5 to 5.5. When sizing of this type of paper isdone, economical sizing is being accomplished using commerciallyavailable rosin size formulations and papermakers alum which are addedinto the pulp slurries used to make the paper. Lately, however, inresponse to demands for long lasting papers, papermakers have beentrying to develop methods .for manufacturing paper under alkaline pHconditions.

to give permanent sizing while being compatible with.

present papermaking procedures.

Briefly, this invention provides a sizing combination of ingredientswhich are particularly useful for sizing textiles and paper products.The sizing combinations comprise a mixture of (1) one or more higheralkyl propiolate or higher alkyl acrylate compounds, or mixtures of suchpropiolates and acrylates and (2) a polyalkyleneimine or a poly(N-methylalkyleneimine), or mixtures thereof having from 2 to 3 carbonatoms in each alkylene moiety. This combination type of sizing operationprovided for by this invention is particularly surprising in view of thesubstantially lowering sizing eifectiveness demonstrated by the alkylpropiolates alone and the complete absence of sizing by thepolyalkyleneimine and/ or poly(N-methylalkyleneimine) component whenused alone. The alkyl propiolate or alkyl acrylate to polyalkyleneimineor po1y(N-methylalkyleneimine) polymer weight ratios may range fromabout 1:10 to about :1, although we prefer to use them in a weight ratioof about 1:1 to 1:3.

. The preferred method of applying the sizing materials to thecellulosic substrate is to add to an aqueous dispersion of the pulp usedto make the cellulosic paper sheet or article an emulsion of the alkylpropiolate or alkyl acrylate and the polyalkyleneimine or poly(N-methylalkyleneimine) in a mixing vessel and then to form sheets orwebs from the treated aqueous pulp slurry in the United States Patent 0ice conventional manner. The alkyl propiolate or alkyl acrylate and thepolyalkyleneimine or poly(N-methylalkyleneimine) may be mixed into oneemulsion prior to adding them to the aqueous pulp slurry or the twocomponents may be added separately. Optimum results are obtained whenthe pH of the treated pulp slurry is adjusted to the basic pH range,preferably at from about 7 to 10. With the higher alkyl acrylates,substantial sizing is lost as pH is lowered much below about 7. Thealkyl propiolates are not as sensitive to pH and form effective sizingagents when used with the polyalkyleneimines orpoly(N-methylalkyleneimine) at pHs ranging from about 4.8 and higher.The alkyl acrylates are also more sensitive to the use of alum in thepapermaking process. As the alum content increases, the effectiveness ofthe alkyl acrylates diminishes. However, the alkyl acrylates incombination with the polyalkyleneimines or poly(N-methylalkyleneimines)provide a high degree of sizing in the basic pH range where no or littlealum is being used. The alkyl propiolates may be used with thepolyalkyleneimines and poly(N-methylalkyleneimine) even in the presenceof alum. Use of more than about 3% alum, based on the dry pulp usedreduces the sizing effectiveness of these materials somewhat, especiallyin the acid pH papermaking range.

Effective sizing of cellulosic substrates may also be accomplished bydipping the cellulosic paper into dilute aqueous emulsions or organicsolvent solutions of the alkyl propiolate and/or the alkyl acrylate andthe polyalkyleneimine or poly(N-methylalkyleneimine). Papers andtextiles in general, including those from synthetic polymeric fibers mayalso be sized with these materials by spraying them on the surface ofthe substrate being sized.

In application to paper sizing the hard sizing is developed with thepreferred alkyl propiolates, such as C C alkyl propiolates and withpolyethyleneimines in the normal drying operation of papermaking. Ifdesired the paper may be cured at room temperature for a few days or atrelatively elevated temperature say -110 C. for from 10 to minutes toenhance the speed of the sizing action. The alkyl propiolates, andmethods fpr preparing them are described in U.S. Patent 3,100,794. Whenthe alkyl propiolates having from 8 to about 12 carbon atoms in thealkyl group are used, they should be used in concentrations of at leastabout 0.3 to 1.0% by weight based on the dry weight of the materialbeing sized. Alkyl propiolates having about 12 carbon atoms and highermay be used in lower concentration down to about 0.05 concentration,based on the substrate, especially if higher quantities of thepolyalkyleneimines are used. As stated above, the preferred unsaturatedesters are the alkyl propiolates having from 16 to about 20 carbonatoms. The propiolate ingredient may be one compound or may be a mixtureof compounds.

The higher alkyl acrylates having from 8 to 30 carbon atoms may beprepared in a similar manner to that described above in preparing thepropiolic acid esters in U.S. Patent 3,100,794. The preferred alkylacrylates are those having from about 16 to about 20 carbon atoms.

The polyalkyleneimines used in this invention are the polymerizationproducts of ethyleneimine or derivatives thereof. Those used in thisinvention are those having from 2 to 3 carbon atoms in each alkylenegroup which are water soluble. Such products are described, for example,in U.S. Patent 2,182,306. The poly(N-methylalkyleneimines) are thepolymerization products of N- methylethyleneimine,N-methylpropyleneimine, or mixtures thereof.

The following examples will further illustrate the nature of theinvention but the invention is not intended to be restricted thereto.

Example 1 This example illustrates the use of the preferred combinationof sizing ingredients in what we call the wet-end method of application.

A typical alkyl propiolate, or acrylate e.g., 0.75 g. of octadecylpropiolate was dissolved in a suitable organic solvent such as xylene ordimethylbenzyl alcohol. The resulting propiolate solution was emulsifiedwith 20 ml. of 0.1% aqueous hexadecyltrimethyl-ammonium bromide.

Cellulose pulp used to make paper was slurried with water to give 2%pulp solids and then refined to 480520 Canadian Standard Freeness. Thechosen polyalkyleneimine, e.g., polyethyleneirnine, was diluted withwater to a concentration of 1%. An amount of this 1% polyethyleneiminesolution equivalent to the desired weight percent of thepolyethyleneimine based on the dry pulp was added to the pulp slurry andstirred.

The pH of the treated aqueous pulp slurry was adjusted to the desiredtest pH, usually 5, 7, or 9 and then a quantity of the propiolate oracrylate aqueous emulsion was added to the pulp slurry to give 1% (orother test concentration of the chemical or chemicals being evaluated)based on the dry cellulose pulp. Handsheets are prepared from thetreated pulp slurries thus obtained on a Noble and Wood machine and thedried paper sheets obtained are tested for the amount of waterrepellancy (sizing) possessed by the sheet by floating a sample of thetreated paper sheet on a standard ink bath having a pH of 1.5, andobserving the time (in seconds) needed for the first traces of a bluecoloration to appear on the observed surface of the test sample. A highnumber of seconds (over 500) is an indication of hard sizing of thepaper by the added chemicals. For some applications, for example, whereslack-sizing is desired, only a moderate degree of sizing (10 to 500seconds) is desired; slack sizing is evidenced by a moderately highnumber of seconds of resistance to ink penetration. Resistance levels ofunder about 10 seconds are taken as an indication of no or minimalsizing efiectiveness of the added chemical or combination of chemicals.

TABLE II Alum content, percent Sizing mk' resistance, seconds pH of pulpslurry When the test papers were cured at 105 C. for 1 hour and thentested, the sizing results were as follows:

TABLE III Sizing ink resistance, seconds Alum content,

pH of pulp slurry percent HOP-CHO Example 3 This example illustrates theuse of mixtures of alkyl propiolates and polyalkyleneimines as effectivesizing agents. For this example, a standard bleached Gatineau sulfitepulp refined to a Canadian Standard Freeness of 500120 ml. as a 2% pulpsolids aqueous slurry of pH 9 was treated with a 1% aqueous emulsion ofa 50:50 molar mixture of the indicated alkyl propiolates in an amountsuflicient to provide varying weight percents of the mixture based onthe dry pulp. The treated pulp was m'ured 15 minutes and thenpolyethyleneimine was added in quantity sufiicient to provide varyingWeight percents thereof based on the dry weight of the pulp used. The

The results are summarized in Table I. treated pulp was mixed another 15minutes to insure TABLE I Compound Percent Compound Percent Cure Inksizing (seconds) octadecyl propiolate 1 Polyethyleneimine 1 79, 000+ Do1 Polypropyleneirnine 1 000+ 1 do 1 7, 000+ Polyethyleneimjne 1 0 0 1Poly(2-hydroxy-1, 3- 1 4 propyleneimine) 263 octadecyl acrylate 1Polyethyleneiminc 1 11, 000+ 11, 000+ Octadecyl propiolate 0. 7

l-hexadecyl propiolate 0. 3 Polyethyleneimine 0. 3 2, 900 2, 300 D0- 0.7--.d0 0.7 N 12,000 9, 500 Octadecyl propiolate 0.3 N 3, 000 2, 450n-Decyl propiolate 0. 7 N o 2, 250 180 Octadeeyl propiolate 6. 0 10,000+ 3 days R.T 30, 000+ Example 2 concentrations, based on the Weightof the dry pulp used. 75

complete dispersion and then handsheets were prepared. The results aresummarized in the following table.

TABLE IV Sizing ink Percent polyresistance, Propiolates Percentethyleneimine seconds Oetadeeyl Z-ethylhexyl. O. 3 0. 3 1, 412 octadecyltridecyl 0. 4 0. 4 1, 975 Tridecyl 2etliylhexyl 0. 4 0. 4 D0 0. 4 0.8 4,500 D0 0. 5 0. 5 350 Example 4 Poly(N-methylethyleneimine) was dissolvedin water and added to a bleached sulfite pulp slurry in an amount togive 1 part of poly(N-methylethyleneimine) to 100 parts of pulp. After15 minutes stirring an emulsion prepared by dissolving octadecylpropiolate in dimethylbenzyl alcohol, then emulsifying this resultingsolution with the aid of Arquad 2HT (a dialkyldimethyl quaternaryammonium chloride) was added to the above treated pulp slurry in anamount to give 1 part of octadecyl propiolate to 100 parts of pulp.Sheets of paper were formed from the treated pulp thus obtained, anddried on a Noble and Wood handsheet machine drier. Ink penetrationresistance time of these sheets was found to be more than 18,000seconds.

What is claimed is:

1. Cellulosic paper sized with a combination of (1) at least one memberof the group consisting of an alkyl acrylate having from 16 to 20 carbonatoms in the alkyl group and an alkyl propiolate having from 8 to about20 carbon atoms in the alkyl group and (2) at least one member of thegroup consisting of a poly-N-methylalkyleneimine and polyalkyleneiminehaving from 2 to 3 carbon atoms in each alkylene group thereof.

2. Sized cellulosic paper as described in claim 1 Wherein the alkylpropiolate (1) is used and is a mixture of two or more alkyl propiolateshaving from 8 to 20 carbon atoms in each alkyl group, and component (2)is a polyalkyleneimine which is a polyethyleneimine.

3. Sized cellulosic paper as described in claim 2 wherein the mixture ofalkyl propiolates (1) is a mixture of Z-ethylhexyl propiolate andtridecyl propiolate.

4. Sized cellulosic paper as described in claim 1 wherein component (1)is an alkyl propiolate and is octadecyl propiolate and component (2) isa polyalkyleneimine which is a polyethyleneimine.

5. A method for preparing sized cellulosic paper which comprises mixingwith an aqueous cellulosic pulp slurry being used to prepare papertherefrom an aqueous dispersion of (1) at least one member of the groupconsisting of an alkyl acrylate having from 16 to 20 carbon atoms in thealkyl group and an alkyl propiolate having from 8 to 20 carbon atoms inthe alkyl groups thereof, also mixing with said aqueous pulp slurry with(2) at least one member of the group consisting of polyalkyleneiminesand poly(N-methylalkyleneimines) having from 2 to 3 carbon atoms in thealkylene groups in concentrations sufiicient to provide at least about0.05% by weight of component (1) and at least about 0.15% by weight ofcomponent (2) based on the weight of the dry pulp, and then forming thetreated aqueous pulp slurry thus obtained into paper.

6. A method as described in claim 5 wherein component (1) is an alkylpropiolate and is used as a mixture of alkyl propiolates having from 8to about 20 carbon atoms in the alkyl groups thereof and component (2)is a polyalkyleneimine having from 2 to 3 carbon atoms in each alkylenegroup.

7. A method as described in claim 5 wherein component (1) is an alkylpropiolate and is octadecyl propiolate and component (2) is apolyalkyleneimine and is polypropyleneimine.

8. A composition comprising (1) at least one member of the groupconsisting of alkyl acrylate having from 16 to 20 carbon atoms in thealkyl group and alkyl propiolates having from 8 to about 20 carbon atomsin the alkyl group and (2) at least one member of the group consistingof polyalkylenepolyimines and poly(N-methylalkyleneimines) having from 2to 3 carbon atoms in the alkylene groups thereof.

9. A composition as described in claim 8 wherein component (l) is analkyl propiolate and component (2) is a polyalkyleneimine and saidcomponents (1) and (2) are present in Weight ratios of from about 1:10to about 10:1 of alkyl propiolate to polyalkyleneimine.

10. A composition as described in claim 9 wherein component (1) is analkyl propiolate and is a mixture of alkyl propiolates having from 8 to20 carbon atoms in the alkyl groups of each molecule and component (2)is a polyalkyleneimine and is a polyethyleneimine.

11. A composition as described in claim 9 wherein the alkyl propiolateis octadecyl propiolate and the polyalkyleneimine is apolyethyleneirnine.

References Cited UNITED STATES PATENTS 3,016,325 l/1962 Pattillochl62l68 X 3,100,794 8/1963 Miller 260-233.3 X 3,350,340 10/ 1967Soenkensen et al.

S. LEON BASHORE, Primary Examiner T. G. FERRIS, Assistant Examiner U.S.Cl. X.R.

